(HY-industry technical centre)

HY-industry titanium grad:

Brief introduction:

With the rapid development of aerospace, automotive lightweight and biomedical materials, the research and application of titanium alloy materials has become one of the research hotspots in the field of materials. The density of titanium alloy is generally about 4.51g/cm3, which is only 60% of steel. However, the mechanical strength of titanium is similar to that of steel. Even some newly developed titanium alloys have exceeded the strength of some high-strength structural steels. Compared with other commonly used structural materials such as steel and aluminum, the specific strength of titanium alloys shows obvious advantages; titanium alloys have high thermal strength and can work for a long time at temperatures of 450 to 500 ° C; good corrosion resistance, pitting corrosion, Acid etching and stress corrosion resistance are particularly strong, and it can work in humid atmosphere and seawater medium. Its corrosion resistance is much better than that of stainless steel. In addition, it has excellent corrosion resistance to alkali, chloride, nitric acid and sulfuric acid. At the same time, titanium alloy can maintain its mechanical properties at low temperature and ultra-low temperature. For example, at -253 ° C, TA7 still has good plasticity. Therefore, titanium alloy can also be used as a low temperature structural material.

However, the processing and manufacturing process of titanium alloys is difficult. In the hot processing of titanium alloy smelting, casting, etc., titanium easily reacts with impurities such as hydrogen, oxygen, nitrogen, carbon, etc., which makes the process quality difficult to guarantee; in addition, its wear resistance is poor, and the cutting process is difficult, resulting in high manufacturing cost. Subject to certain restrictions. Although it is very rich in the earth’s crust, it is 0.63%, second only to oxygen, silicon, aluminum, iron, calcium, sodium, potassium, magnesium, hydrogen, ranking 10th in the element distribution sequence, but the development of titanium alloy Relative to steel, aluminum, etc. are still relatively backward. As early as 1791, people discovered titanium from ores such as rutile (TiO2) and ilmenite (FeTiO3), but how to extract titanium from these ores has been plagued by people for more than 100 years until 1910. Pure titanium was produced for the first time, which opened the application era of titanium.

China’s titanium reserves rank first in the world, accounting for about 46% of the world’s total titanium. With the advancement of science and technology, China has formed an industrial chain from titanium ore to titanium ingots to titanium alloy processing. At present, titanium and its alloys have been widely used, and the titanium industry is growing at an average annual growth rate of about 8%. Up to the aerospace, spacecraft, down to the deep sea, oil wells, titanium alloy applications are more and more extensive. HY-industry has cooperated with many science and technology institutes and research institutes in the past 20 years to develop titanium alloy materials. It has a certain reputation and good reputation in the field of titanium alloy materials in China.

HY-industry titanium grad:

Industrial application of titanium and titanium alloys

Aerospace field

Titanium alloy has excellent properties such as low density and high specific strength, so it is an ideal aerospace structural material. At present, the application of titanium alloy in the aerospace industry is more and more popular.

In the 1950s, only a few non-load-bearing members, such as rear fuselage insulation panels, air ducts, and tailgates, were made of titanium alloys in aviation aircraft. Since the 1960s, the middle fuselage has been separated. Important bearing members such as frames, beams, and flaps are also gradually replacing titanium with titanium. As far as the current trend is concerned, the more advanced the new aircraft, the more wide-body aircraft, the greater the amount of titanium. The density of C-5 titanium alloys that began service in the United States in 1970 was 6%, and the subsequent C-17 increased to 10.3%. After 2006, the amount of titanium used in the fourth generation of US fighter F22 was as high as 39% to 41%. China has also made great progress in the research and application of titanium alloys.

The quality of the titanium parts of the J-7 aircraft put into production in the 1960s was only 9 kg, and the quality of the J-8II type titanium parts produced in the 1980s reached 93 kg. In 2002, the Kunlun turbojet engine was designed and shaped, and the amount of titanium was increased to 15%. The amount of titanium used in China’s first turbofan engine was increased to 25%.

Since the 1970s, titanium alloys have been used extensively on civil aircraft. For example, a Boeing 787 uses up to 136 tons of titanium, which accounts for 15% of the total mass. In addition, pressure vessels, fuel tanks, fasteners, rocket housings, etc. in the aerospace industry are also being manufactured using titanium alloys.

Application in the field of ships:

Titanium is a chemically active element with a high affinity with oxygen. When placed in air, it reacts with oxygen to form a dense TiO2 protective film on the surface, which protects the titanium alloy from external media. Therefore, titanium alloy has good corrosion resistance, can exhibit good chemical stability in acid, alkali and oxidizing medium, corrosion resistance is better than existing stainless steel and most non-ferrous metals, and even comparable to platinum. The hardness of pure titanium is about HV150, which is not high, but the hardness is very obvious after adding alloying elements. For example, the surface hardness of TA4 is roughly HRC30, which exceeds the conventional stainless steel and ordinary carbon steel materials. It can exceed HRC60; under low temperature and ultra-low temperature conditions, titanium still maintains its original performance, strength and hardness are maintained at a high level, so titanium alloy is very suitable for ship parts. For example, a submarine made mainly of titanium alloy can withstand a depth of 4 500 m without damage, and this index of a general steel submarine is about 300 m.

Since the 1960s, many countries have begun to study the application of titanium alloys to the shipbuilding industry, such as the United States, Russia, Japan, China, the United Kingdom, France and Germany.

Titanium alloy has unique physical properties (including magnetic properties), high specific strength and impact resistance, excellent corrosion resistance and erosion resistance, which have been widely used in ships, especially in the United States and Russia. Like military powers, research on titanium alloys is clearly ahead of the world. For example, Russia is the first country in the world to develop and use marine titanium alloys. At present, the system of marine titanium alloy series has been constructed, and various series of strength grade titanium alloy products have been developed and successfully applied to hulls, ship engines and power plants. In the parts and corresponding equipment on ships, the production process of titanium and titanium alloy products is relatively mature; the United States has more research on titanium alloys for ships, which is based on the use of titanium alloys for aviation, in the nuclear High-performance titanium alloys are used for seawater cooling systems, seawater systems and fire-fighting systems, structural components, propellers, etc. of ships on different hulls such as power carriers, guided missile cruisers, and guided missile frigates.

China has strengthened its research on marine titanium alloys since the 1960s. For decades, the research and application level of marine titanium alloys have achieved remarkable results, and a relatively complete series of marine titanium alloys has been formed, which basically meets the requirements for different strength titanium alloys such as naval vessels, submarines and deep submersibles. For example, low-strength titanium alloys with a yield strength below 490 MPa have excellent plasticity, such as Ti31 for heat exchangers and condensers, and medium-strength titanium alloys between 490 and 790 MPa, such as ZTi60. Pressure-resistant system castings; high-strength titanium alloys above 790 MPa have also been applied to heat-resistant and corrosion-resistant parts in marine power engineering such as propellers, high-pressure vessels, and ejection devices.

In recent years, in order to further improve the equipment level of the Chinese navy, China attaches great importance to the research and development of new materials in the field of ships. The special properties of titanium alloys make it have a very broad application prospect in the field of ships.

In the past 20 years, HY-industry has provided many high-quality titanium alloy materials for Chinese military workers and has a complete quality standard system.

Chemical industry

Titanium has good corrosion resistance and is one of the important structural materials in equipment used under the action of corrosive media such as chemical industry. The use of titanium alloy instead of stainless steel, nickel-based alloy and other rare metals can effectively reduce operating costs and extend equipment life, which is of great significance for improving product quality, energy saving and consumption reduction.

1) Application in chlor-alkali industry

Since the chlor-alkali industry uses electrolytic saturated sodium chloride (NaCl) solution to prepare sodium hydroxide (NaOH), etc., and further processes the series of chemical products, the requirements for preventing corrosion are very high. Therefore, the demand for titanium alloy materials in the chlor-alkali industry is still very large. At present, in the chlor-alkali industry, equipment prepared by using titanium alloy materials includes a wet chlorine cooler, an anode electrolysis tank, a dechlorination tower heating tube, a vacuum dechlorination pump, and the like. For example, in the process of electrolyzing caustic soda production, a large amount of high-temperature wet chlorine gas with a temperature of 75-95 ° C is generated, which seriously pollutes the environment. The wet chlorine gas cooler made of titanium alloy is used instead of the graphite cooler to obtain good effect and some service life. More than 20 years.

2) Titanium alloy materials have also been widely used in the soda ash industry.

Soda ash is one of the most basic chemical raw materials, and its production process is mainly synthetic alkali method, including ammonia alkali method and combined alkali method. Regardless of the process, ammonia (NH3) and carbon dioxide (CO2) are mostly used as the gaseous medium, and the liquid medium is mostly the solution with a higher concentration of chloride (Cl-). In the past, most of the main equipments such as carbonization tower tubes, coolers, and crystal external coolers used carbon steel and cast iron materials. The reaction tower was seriously corroded, and leakage often occurred. After the use of titanium alloy materials, great changes have taken place. For example, the Dalian Chemical Industry Co., Ltd. alkali plant purchased the TA2 pipe of Baoji Nonferrous Metals Processing Factory instead of the cast iron pipe in the ammonia condenser. No corrosion leakage was observed after 14 years of production. Extends the service life.

Application of high-end oil well pipe field

Since Edwin Drake drilled the first oil well in Titusville, Pennsylvania in 1859, the oil industry has developed rapidly, and oil and natural gas have replaced coal as the largest source of energy for human use. Pipe is the most expensive material used in oil and gas drilling. It not only consumes a lot of money, but also spends a lot of money. More importantly, its quality is of great importance to the petroleum industry, directly affecting the single well life of oil and gas wells, and thus affecting the overall benefits of the oil industry.

With the development of modern drilling technology, China’s oil drilling began to develop into deeper and more demanding oil and gas wells. Ordinary material oil well pipe can not meet the demand. With the further deepening of the mining depth, the service environment of the oil well pipe extends to extremely harsh conditions where high temperature and high pressure, high CO2, hydrogen sulfide (H2S), Cl- and other corrosive media coexist.

Nickel-based alloys are commonly used in the raw materials of traditional high-end anti-corrosion oil well pipes. However, in the past two years, the limitations of nickel-based alloys have gradually appeared, which are expensive and heavy. In some harsh environments, such as sulfur corrosion resistance, it cannot resist. Titanium alloys are lighter and have better corrosion resistance. Through a large number of experiments, Tianjin Pipe Group has added some alloying elements to ensure the corrosion resistance while improving the strength and toughness. In addition, through the improvement of machining technology, special threaded threads complying with the characteristics of titanium alloys are designed to ensure the connection of the oil pipes. Sealing, the titanium alloy tubing developed and produced by the Steel Pipe Group has a depth of more than 6 300m, making it the world’s first manufacturer to develop titanium alloy tubing and apply it to ultra-deep high-sulfur oil and gas fields.

HY-industry titanium grad:

The application of titanium and titanium alloys in civil life

Titanium and titanium alloys are not only indispensable structural materials in the aerospace industry, but also widely used in shipbuilding, chemical engineering, and oil exploitation. At present, it is gradually being developed into civilian industries such as biomedicine, glasses, jewelry, mobile phones, computers, etc., and is growing at a certain rate every year.

Biomedical field

Titanium is an ideal medical metal material with good biocompatibility. As early as the mid-1980s, the United States began to develop biocompatible titanium alloys containing no elements such as aluminum and vanadium for orthopedic surgery. Current titanium alloy materials are mainly used in the manufacture of medical devices, prostheses or artificial organs implanted in the human body, as well as titanium alloys for auxiliary therapeutic devices.

Since the 1970s, China has made remarkable achievements in the research of titanium and titanium alloys for biomedical applications. At present, it is possible to manufacture medical devices with titanium alloy materials, artificial hip joints, knee joints, shoulder joints, flank joints, and cranial bones. Heart flaps, bone clips, etc.

For example, titanium alloy porcelain teeth, which have high strength and low price, are a kind of porcelain teeth which are commonly used in China at present. Titanium alloy porcelain teeth, beautiful appearance, stable color, can restore the shape and function of the tooth well, especially suitable for people sensitive to nickel ions, can avoid the occurrence of gum bleeding and black gums, in addition to its corrosion resistance It is also very strong and it is not easy to get dark. This material is more biocompatible than non-precious metal porcelain teeth and has a service life of up to 10 years.

Applications in the glasses industry

Titanium is increasingly becoming a new type of spectacle frame material. The spectacle frame made of titanium alloy has high hardness and good flexibility, and is ergonomic, elastic, long-term use, no deformation, no fading, soft and smooth touch, no cold sense of other metal frames, titanium has no effect on the human body. Toxic, without any radiation. In addition, titanium can form a “memory alloy” with nickel, that is, a memory titanium alloy. After the spectacle frame is deformed, it can be restored by washing with water at a specific temperature.

The production process of titanium frames is very demanding. It not only has many processing steps, but also requires special processing equipment and special welding technology and electroplating process. Therefore, the price of titanium frames is higher than other metal, sheet or plastic frames. . However, with the improvement of people’s living standards, the demand for titanium alloy frames is increasing. It is necessary for the majority of scientific and technological workers to continuously research and develop various new technologies and techniques to improve the production process and make them more acceptable to more people.

Applications in the jewelry industry

Compared with precious metals such as gold and platinum, titanium, as a new type of jewelry material, not only has an absolute advantage in price, but also has advantages in other aspects.

light, titanium alloy density of 27% of gold, in the production of earrings, necklaces and other jewelry advantages, can be designed to process some large and unique special jewelry.

Titanium has good corrosion resistance, and the oxide film formed on the surface of titanium is extremely complete and compact. After partial damage, it will repair itself in an instant without affecting its appearance.

Good biocompatibility, people will not cause allergies after long-term contact, especially those who are allergic to metal can wear it with confidence.

Titanium can be colored, and the color can be changed by changing the thickness of the oxide film without the need for additional elements. The colors that can be made now are gold, black, blue, brown, flowers, etc., and the colors are fashionable.

Titanium has high hardness and is not easy to be deformed. It does not need to be reshaped after wearing for a period of time.

HY-industry titanium grad:

UNS R54620 (Titanium alloy 6Al-2Sn-4Zr-2Mo)

UNS R56400 (Titanium alloy 6Al-4V)

UNS R56401 (Titanium alloy 6Al-4V ELI)

UNS R56410 (Titanium alloy 10V-2Fe-3Al)

development trends and difficulties overcome

Although titanium and titanium alloys have achieved remarkable development, due to their poor process performance, titanium refining and processing costs are quite high, which limits the development and application of alloy systems.

Processing technology needs to be improved

Since titanium has high chemical activity at high temperatures and is easily contaminated by elements such as oxygen, nitrogen, and carbon, the processing and manufacturing process of titanium alloys is very high. Therefore, the cost of manufacturing titanium alloy materials is very expensive, and the application fields are limited. Currently, they are mostly used in high-tech industries such as aircraft structures, aircraft, petroleum and chemical industries.

Titanium alloys have poor rigidity and poor thermal conductivity, resulting in local high temperatures and sticky knives, so the processing process is difficult. Generally, the workability of titanium alloy is only 20% to 40% of 45 steel, hardness <HB300, and the sticking knife is serious; HB>370 is too hard to process. In addition, titanium is highly chemically active and easily combines with gaseous impurities. When the temperature exceeds 600 ° C, titanium is oxidized into an embrittlement layer, a so-called “tissue gelatinization layer”; hydrogen brittleness is generated with hydrogen; and hard and brittle titanium nitride (TiN) is formed at a high temperature with nitrogen, which exacerbates tool wear. In addition, titanium alloys can chemically bond with the elements of the tool material, causing severe bond wear.

How to further develop the purification and alloying process of titanium alloys, and optimize the machining methods to further reduce the manufacturing cost of titanium alloy products is the key to promote the wide application of titanium alloys

Research and development of high value-added high-end products

At present, titanium alloy processing enterprises also have the phenomenon of low technical level and overcapacity. Therefore, enterprises need to intensify innovation and produce high-value-added high-end products to provide strong competition for enterprises. At the beginning of December 2016, the 20-ton titanium ingot produced by Qinghai Synthetic Titanium became the largest single-titanium ingot in the whole country and even in Asia. On this basis, the 500mm thick oversized ingot was successfully produced and can be rolled straight. It is a 200mm tape slab, and then directly rolls a wide plate with a width of more than 1.8m, thus subverting the traditional rolling process and filling the gap of international technology. This technology greatly shortens the processing cycle, reduces the processing links, increases the yield, reduces the processing cost, and expands the competitive advantage of the product.

Industry standards

The manufacturing process of titanium alloy and its products is relatively high, and the requirements for production equipment and processing equipment are also very high. The quality control of the products also has certain difficulties. Therefore, the application of titanium materials still lacks standardized industry standards. This means that the quality control of titanium alloys and their products cannot meet the uniform requirements, resulting in uneven product quality, which is extremely unfavorable for the expansion of the application of titanium alloys.

HY-industry titanium grad:

UNS R54620 (Titanium alloy 6Al-2Sn-4Zr-2Mo)

UNS R56400 (Titanium alloy 6Al-4V)

UNS R56401 (Titanium alloy 6Al-4V ELI)

UNS R56410 (Titanium alloy 10V-2Fe-3Al)

Conclusion

The development prospects of titanium alloys can be described as bright and broad. Because of its excellent performance: high specific strength, low density, corrosion resistance, etc., it has applications in many fields, such as: aviation, military, marine, petrochemical, etc., and because titanium alloy has good compatibility with human body. The medical field has achieved very rapid development.

The various advantages of titanium alloy have attracted people’s attention, but its expensive price has made people have to be discouraged and limited in application. It is believed that with the improvement and improvement of titanium smelting technology and processing technology, the varieties of titanium and titanium alloy products and their quality control level will be further expanded, and their application fields will also be expanded, especially in the civilian industry, like tableware. Jewelry, mobile phones, computers, crutches and other civilian leisure products can be realized as long as people have demand.